When a television is initially installed in a user's home after purchase, the receiver of the TV automatically searches for channels that are available in the area and records information pertaining to available channels in memory using a data structure known as a “channel map”. The channel map includes information for each available channel, such as channel frequency. Without a channel map the receiver otherwise would tune to the next higher channel in response to a “channel up” command regardless of whether a signal is present. This also would be the case for channel changes for decrementing the channel number. The search and record function is known as “autoprogramming” because it automatically programs the TV with information pertaining to available channels.
As understood herein, with the advent of digital televisions and hundreds of satellite channels, digital ones of which might in fact carry several sub-channels, the autoprogramming function discussed above can consume much time. This is not only because of the increased number of channels but also because digital channels are more complicated to map, requiring not just a frequency map but also various decoding information.
As also understood herein, the location of a mobile TV receiver frequently can change and with it the available channels, precipitating another autoprogramming cycle even if the location of the receiver and thus the identity of available channels haven't changed much. Indeed, as recognized herein due to variable reception conditions such as elevation, shielding by buildings or terrestrial objects, etc, a mobile receiver may not be able to detect all the potentially available channels in a given location at a given time, although such channels might become immediately available when the receiver is moved a relatively short distance.